This page explains what happens, so you can read it before you decide and without signing in.
Sign in as the workspace owner and open Preferences → Close this workspace. You will be asked to type the workspace name to confirm. You can also do it from the mobile app: Settings → Close this workspace.
Only the owner can close a workspace. An admin can remove people and change settings, but losing the whole workspace should not be something a colleague can do on your behalf.
Everything belonging to the workspace is permanently deleted and cannot be recovered by us or by you: monitors and their history, check results, incidents and their timelines, status pages, chat and war-room messages, uploaded files, integrations and their stored credentials, and every member account that belongs to no other workspace.
During those 30 days the owner can cancel from the same screen. Monitoring resumes within a minute, with every monitor's settings exactly as they were — scheduling a deletion never changes them.
After the 30 days there is nothing left to restore. That is the point of the notice period rather than a limitation of it.
Records we are required to keep for tax and accounting — invoices and payment records — are retained for as long as the law requires, and are not usable to sign in or to identify what you monitored.